Charged particle production in Pb-Pb and p-Pb collisions measured by the ATLAS detector

The ATLAS experiment at the Large Hadron Collider measures charged hadron spectra in Pb+Pb and p+Pb collisions. The results are compared to the p+p spectra of charged hadrons at the same centre-of-mass energy. Charged hadron distributions from Pb+Pb are compared to charged particle cross-sections in p+p collisions at sqrt(s) = 2.76 TeV, reference cross-section for p+Pb at sqrt(sNN) = 5.02 TeV is reconstructed using sqrt(s) = 2.76 TeV and 7 TeV p+p results. These allow for a detailed comparison of the collision systems in a wide transverse momentum and rapidity ranges in different centrality intervals. The nuclear modification factors RAA and RpPb are presented as a function of centrality, pT, η. The charged particle RAA are found to vary significantly as a function of transverse momentum, shows a pronounced minimum at about 7GeV. Above 60GeV, RAA is consistent with a flat, centrality-dependent, value within the uncertainties. RpPb results show strong rapidity dependence in the region of so-called Cronin peak at about 2 GeV and above pT of 10 GeV show anomalous enhancement.